fix(labels): Update chart labels (#456)
fix(labels): Update chart labels (#456)

The update method introduced in #410 and merged in #414 removed the ability of updating chart labels dynamically.

Closes #420 #445
valor-software/ng2-charts,Blueliv/ng2-charts,Blueliv/ng2-charts,valor-software/ng2-charts,valor-software/ng2-charts,valor-software/ng2-charts